Solid dose delivery vehicle and methods of making same

ABSTRACT

The present invention encompasses a solid dose delivery vehicle for ballistic administration of a bioactive material to subcutaneous and intradermal tissue, the delivery vehicle being sized and shaped for penetrating the epidermis. The delivery vehicle further comprises a stabilizing polyol glass loaded with the bioactive material and capable of releasing the bioactive material in situ. The present invention further includes methods of making and using the solid dose delivery vehicle of the invention.

FIELD OF THE INVENTION

[0001] The present invention relates generally to solid dose vehiclesfor delivery of bioactive materials and, more specifically, to soliddose delivery vehicles comprising a stabilizing polyol and a bioactivematerial. Methods of their making and uses thereof are also provided.

BACKGROUND OF THE INVENTION

[0002] Solid dose delivery of bioactive materials to mucosal, dermal,ocular, subcutaneous, intradermal and pulmonary tissues offers severaladvantages over previous methods such as topical applications ofliquids, transdermal administration via so-called “patches” andhypodermic injection. In the case of injection, solid dose delivery canreduce the risk of infection by eliminating the use of needles andsyringes, provide for more accurate dosing than multidose vials, andminimize or eliminate the discomfort which often attends hypodermicinjection. Several solid dose delivery systems have been developedincluding those utilizing transdermal and ballistic delivery devices.

[0003] Topical delivery is utilized for a variety of bioactive materialssuch as antibiotics for wound healing. These topical ointments, gels,creams, etc. must be frequently reapplied in order to remain effective.This is particularly difficult in the case of burn wounds.

[0004] Devices used for administering drugs transdermally usuallycomprise laminated composites with a reservoir layer of drug with thecomposite being adhered to the skin, i.e., transdermal patch, such asdescribed in U.S. Pat. No. 4,906,463. However, many drugs are notsuitable for transdermal delivery, nor have transdermal drug releaserates for those capable of transdermal delivery been perfected.

[0005] Subdermal implants have also been formulated for slow release ofcertain pharmaceutical agents for extended periods of time such asmonths or years. A well-known example is the Norplant® for delivery ofsteroid hormones. Such implants are usually constructed of an inner,drug-filled core which is relatively permeable to the drug and an outermatrix which is relatively impermeable to the drug. Both inner core andouter matrix are generally formed from polymers. The implants releasedrugs by dissolution of the drug in the inner core and slow releaseacross the outer matrix. The inner core may substantially dissolve overtime, however, in devices currently in use, the outer matrix does notdissolve. Implants are placed subcutaneously by making an incision inthe skin and forcing the implants between the skin and the muscle. Atthe end of their use, if not dissolved, these implants are surgicallyremoved. U.S. Pat. No. 4,244,949 describes an implant which has an outermatrix of an inert plastic such as polytetrafluoroethylene resin. PCT/GB90/00497 describes slow release vitreous systems for formation ofimplantable devices. These implants are bioabsorbable and need not besurgically removed. However, insertion is by surgical means. Moreover,these devices may be limited in the type of bioactive material that canbe incorporated. In the case of polymeric implants, bioactive materialsthat cannot withstand organic solvents are not suitable for use. In thecase of vitreous systems, bioactive materials that cannot withstand theelevated temperatures necessary to form the implants are unsuitable foruse. In all cases, bioactive materials that are unstable at bodytemperature, particularly over long time periods, are unsuitable foruse.

[0006] A variety of formulations have been provided for administrationin aerosolized form to mucosal surfaces, particularly “by-inhalation”(naso-pharyngeal and pulmonary). Compositions for by-inhalationpharmaceutical administration generally comprise a liquid formulation ofthe pharmaceutical agent and a device for delivering the liquid inaerosolized form. U.S. Pat. No. 5,011,678 describes suitablecompositions containing a pharmaceutically active substance, abiocompatible amphophilic steroid and a biocompatible (hydro/fluoro)carbon propellant. U.S. Pat. No. 5,006,343 describes suitablecompositions containing liposomes, pharmaceutically active substancesand an amount of alveolar surfactant protein effective to enhancetransport of the liposomes across a pulmonary surface.

[0007] One drawback to the use of aerosolized formulations is thatmaintenance of pharmaceutical agents in aqueous suspensions or solutionscan lead to aggregation and loss of activity and bioavailability. Theloss of activity can be partially prevented by refrigeration; however,this limits the utility of these formulations. This is particularly truein the case of peptides and hormones. For instance, syntheticgonadotropin releasing hormone (GnRH) analogs, such as the agonistnafarelin or the antagonist ganirelex are designed for high potency,increased hydrophobicity and membrane binding. The compounds havesufficient hydrophobic character to aggregate in aqueous solution and toform an ordered structure that increases in viscosity with time. Thusbioavailability in nasal or pulmonary formulations may be prohibitivelylow. The use of powdered formulations overcomes many of these drawbacks.The requisite particle size of such powders is 0.5-5 microns in order toattain deep alveolar deposition in pulmonary delivery. Unfortunately,powders of such particle size tend to absorb water and clump and thusdiminish deposition of the powder in the deep alveolar spaces. Althoughpowders with larger particle size are suitable for delivery to thenaso-pharynx region, the tendency of powders to clump decreases theavailable particle surface area for contact with, and absorptionthrough, these membranes. Devices which disaggregate clumps formed byelectrostatic interactions are currently in use (e.g., the Turbohaler™);however, these do not disaggregate moisture induced clumps and it wouldbe advantageous to have powders which do not absorb moisture and clumpand thus increase the effective pulmonary concentration of the drug.

[0008] Solid dose delivery vehicles for ballistic, transdermal,administration have also been developed.

[0009] For example, in U.S. Pat. No. 3,948,263, a ballistic animalimplant comprised of an exterior polymeric shell encasing a bioactivematerial is described for veterinary uses. Similarly, in U.S. Pat. No.4,326,524, a solid dose ballistic projectile comprising bioactivematerial and inert binder without an exterior casing is disclosed.Delivery is by compressed gas or explosion. Gelatin coveredtranquilizing substances carried by ballistic projectiles for implantare also described in U.S. Pat. No. 979,993.

[0010] The above-described ballistic devices, however, are suited tolarge animal veterinary applications due to their relatively large size,on the order of millimeters. Ballistic delivery at the cellular levelhas also been successful. The general principle of ballisticadministration is the use of a supersonic wavefront, created by therelease of compressed gas, to propel the particles contained in anadjoining chamber. For example, nucleic acids adsorbed on tungstenmicroprojectile particles have been successfully delivered to livingepidermal plant cells. See Klein Nature 327:70-73 (1987). A bettercontrolled device is the particle inflow gun (PIG). Vain et al. (1993)Plant Cell, Tissue and Organ Culture 33:237-246. Devices have beendescribed which fire ampules containing medication using gas pressure.U.S. Pat. No. 4,790,824; and PCT/GB 94/00753. Several devices thatinject fluids have also been described. U.S. Pat. Nos. 5,312,335 and4,680,027. There are few existing formulations suitable for ballisticdelivery. Powder formulations of pharmaceuticals in their present formare unsuitable for ballistic administration. Particles of availablepowder forms are generally irregular, varying in size, shape anddensity. This lack of uniformity leads to powder deposit and loss at theskin surface during administration, as well as problems in control andconsistency of the depth of delivery to subcutaneous and intradermaltissues.

[0011] Thus it would be advantageous to provide solid dose drug deliveryvehicles of defined size, shape and density, to ensure more uniformdistribution. Additional benefits would accrue if the shape of thevehicle could be controlled to facilitate or control penetration of theepidermis and hard layers of the skin. Small delivery vehicle size,preferably coupled with high momentum delivery, would also increase thecomfort of administration and minimize tissue damage. The manufacture ofsuch a solid dose delivery vehicle should be such that neither thedelivery vehicle nor the bioactive substance being delivered is damagednor its efficacy decreased. Furthermore, the bioactive substance shouldremain stable when loaded within or on the vehicle so that efficaciousadministration can be achieved, and to facilitate storage of the loadeddelivery vehicle. Manufacture of the solid dose delivery vehicle and itsloading with bioactive material and the administration of the vehicleshould also be relatively simple and economical.

[0012] All references cited herein are hereby incorporated by reference.

SUMMARY OF THE INVENTION

[0013] The present invention encompasses a solid dose delivery vehiclesuitable for therapeutic administration of a wide variety of substances,comprising a stabilizing polyol and a bioactive material. Preferredbuffers, adjuvants and additional stabilizers are also provided. Thedelivery vehicle can be sized and shaped for a variety of modes ofadministration.

[0014] The invention further includes a solid dose delivery vehiclecomprising an outer portion comprising a water soluble glassy and/orpolymeric material having a hollow compartment therein, and an innerportion residing in the compartment, the inner portion comprising atleast one stabilizing polyol and a therapeutically effective amount ofat least one bioactive substance.

[0015] The invention also encompasses methods of delivering a bioactivematerial by providing a solid dose delivery vehicle described above andadministering the vehicle to the tissue. Administration can be bymucosal, oral, topical, subcutaneous, intradermal and by-inhalation.

[0016] The invention further encompasses methods of making the soliddose delivery vehicle. The stabilizing polyol, bioactive material andany other components are mixed and processed by a wide variety ofmethods, including milling, spray drying, freeze drying, air drying,vacuum drying, fluidized-bed drying, co-precipitation and critical fluidextraction. The dried components can be heated to fluidize the glasswhich can then be drawn or spun into solid or hollow fibers. The driedcomponents can also be mixed in aqueous or organic solutions and dried,such as by spray drying, freeze drying, air-drying, vacuum drying,fluidized-bed drying, co-precipitation and critical fluid extraction.

[0017] The invention further provides methods of making vehiclessuitable for slow or pulsatile release of bioactive substances. Themethods include combining bioactive material in solid solutions instabilizing glass-forming polyol and other glass formers withdissolution or degradation rates slower than that of the glass-formingpolyol, and processing the components as described above. The ratio ofmaterials can be controlled so as to provide a wide range of narrowlydefined release rates. The coformulations of stabilizing polyol andother water-soluble and/or biodegradable glasses, plastics and glassmodifiers produced thereby are also encompassed by the presentinvention.

[0018] The invention further provides methods of making deliveryvehicles of glasses of hydrated carbohydrates hydrates with increased Tgand the compositions obtained thereby. The method comprises adding amodifier, preferably a protein, in an amount sufficient to elevate theTg, to the carbohydrate and processing according to a method describedherein. The modifier may be an inert material or may be the bioactivematerial. The product obtained may be combined with stabilizing polyolswith a Tg less than that of the modified carbohydrate to form a slowand/or pulsatile delivery system.

[0019] The vehicles and methods of the invention also encompass vehicleswhich comprise fibers, spheres, particles and needles. Preferably thesevehicles are fibers, spheres, particles and needles. The vehicles can beeither microscopic or macroscopic.

[0020] A wide variety of bioactive materials are suitable for use inaccord with the present invention, including, but not limited to,therapeutic and prophylactic agents. The delivery vehicle and methods ofthe present invention provide for a variety of dosing schemes fordelivery of the bioactive material and are suitable for both veterinaryand human applications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a graph depicting typical particle size distribution ofmicronized trehalose glass powder suitable for administration byinhalation.

[0022]FIG. 2A is a graph depicting the sharp particle size distributionfor trehalose/MWPB glass powder. FIG. 2B is a graph depicting thewetting of various trehalose/MWPB glass powders after storage at ambienttemperature and relative humidities.

[0023]FIG. 3 is a graph depicting the sharp particle size distributionfor trehalose glass powder obtained by spray-drying in a Lab-plant spraydryer.

[0024]FIG. 4 is a graph depicting a comparison of the sharp particlesize distribution for trehalose glass powders prepared with twodifferent spray-dryers (Lab-plant and Buchi, as indicated).

[0025]FIG. 5 is a graph depicting the release of a dye (Mordant Blue 9)from coformulated melt glasses of trehalose octaacetate (TOAC) andraffinose undecaacetate (RUDA).

[0026]FIG. 6A is a graph depicting the resistance of horseradishperoxidase to acetone effected by drying the enzyme with trehalose. FIG.6B is a graph depicting the resistance of alkaline phosphatase toacetone effected by drying the enzyme with trehalose.

[0027]FIG. 7 is a graph depicting the effect of a glass modifier on theTg of Trehalose.

[0028]FIG. 8 is a graph depicting the effect of a glass modifier on theTg of maltose.

DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention comprises a solid dose delivery vehicle formucosal, oral, topical, subcutaneous and intradermal and by-inhalationadministration comprising a stabilizing polyol and a therapeuticallyeffective amount of a bioactive material. By “solid dose” as usedherein, is meant that a bioactive material delivered by the vehicle isin solid rather than liquid or aqueous form. It has now been found thatstabilizing polyols can be formulated into solid vehicles suitable fordrug delivery. These stabilizing polyols have been found to beparticularly useful where otherwise denaturing conditions would renderimpossible the formulation of solid dosage forms of bioactive materials.In particular, such conditions include elevated temperatures and thepresence of organic solvents.

[0030] The compositions exist as solid solutions of the bioactivematerial in stabilizing polyol-glass continuous phases. Previous studieshave shown that in this form the product is resistant to hightemperatures with the exact temperatures depending on the stabilizingpolyol used. Thus, the compositions can be processed as glassy melts forbrief periods without being damaged by the processing. In the same way,the stabilizing polyol containing the product would be resistant todamage during sintering with nitrate and/or carboxylate and/orderivatized carbohydrate and/or other glass-forming substances.

[0031] Examples of types of bioactive materials that may be used in thevehicle and methods of the invention include any pharmaceutical agents,including, but not limited to, antiinflammatory drugs, analgesics,antiarthritic drugs, antispasmodics, antidepressants, antipsychotics,tranquilizers, antianxiety drugs, narcotic antagonists, antiparkinsonismagents, cholinergic agonists, chemotherapeutic drugs, immunosuppressiveagents, antiviral agents, antibiotic agents, appetite suppressants,antiemetics, anticholinergics, antihistaminics, antimigraine agents,coronary, cerebral or peripheral vasodilators, hormonal agents,contraceptives, antithrombotic agents, diuretics, antihypertensiveagents, cardiovascular drugs, opioids, and the like.

[0032] Suitable bioactive materials also include therapeutic andprophylactic agents. These include, but are not limited to, anytherapeutically effective biological modifier. Such modifiers include,but are not limited to, subcellular compositions, cells, bacteria,viruses and molecules including, but not limited to, lipids, organics,proteins and peptides (synthetic and natural), peptide mimetics,hormones (peptide, steroid and corticosteroid), D and L amino acidpolymers, oligosaccharides, polysaccharides, nucleotides,oligonucleotides and nucleic acids, including DNA and RNA, proteinnucleic acid hybrids, small molecules and physiologically active analogsthereof. Further, the modifiers may be derived from natural sources ormade by recombinant or synthetic means and include analogs, agonists andhomologs. As used herein “protein” refers also to peptides andpolypeptides. Such proteins include, but are not limited to, enzymes,biopharmaceuticals, growth hormones, growth factors, insulin, monoclonalantibodies, interferons, interleukins and cytokines. Organics include,but are not limited to, pharmaceutically active chemicals with amino,imino and guanidino groups. Suitable steroid hormones include, but arenot limited to, estrogen, progesterone, testosterone and physiologicallyactive analogs thereof. Numerous steroid hormone analogs are known inthe art and include, but are not limited to, estradiol, SH-135 andtamoxifen. Many steroid hormones such as progesterone, testosterone andanalogs thereof are particularly suitable for use in the presentinvention as they are not absorbed transdermally and, with the exceptionof a few analogs, are destroyed upon oral administration by theso-called hepatic first pass mechanism. Therapeutic agents prepared bythe methods described herein are also encompassed by the invention. Asused herein, “nucleic acids” includes any therapeutically effectivenucleic acids known in the art including, but not limited to DNA, RNAand physiologically active analogs thereof. The nucleotides may encodesingle genes or may be any vector known in the art of recombinant DNAincluding, but not limited to, plasmids, retroviruses andadeno-associated viruses. Preferably, the nucleotides are administeredin the powder form of the solid dose vehicle.

[0033] Compositions containing prophylactic bioactive materials andcarriers therefore are further encompassed by the invention. Preferablecompositions include immunogens such as vaccines. Suitable vaccinesinclude, but are not limited to, live and attenuated viruses, nucleotidevectors encoding antigens, bacteria, antigens, antigens plus adjuvants,haptens coupled to carriers. Particularly preferred are vaccineseffective against diphtheria, tetanus, pertussis, botulinum, cholera,Dengue, Hepatitis A, C and E, hemophilus influenza b, herpes virus,Hylobacterium pylori, influenza, Japanese encephalitis, meningococci A,B and C, measles, mumps, papilloma virus, pneumococci, polio, rubella,rotavirus, respiratory syncytial virus, Shigella, tuberculosis, yellowfever and combinations thereof. Vaccines may also be produced bymolecular biology techniques to produce recombinant peptides or fusionproteins containing one or more portions of a protein derived from apathogen. For instance, fusion proteins containing the antigen ofinterest and the B subunit of cholera toxin have been shown to induce animmune response to the antigen of interest. Sanchez et al. (1989) Proc.Natl. Acad. Sci. USA 86:481-485.

[0034] Preferably, the immunogenic composition contains an amount of anadjuvant sufficient to enhance the immune response to the immunogen.Suitable adjuvants include, but are not limited to, aluminum salts,squalene mixtures (SAF-1), muramyl peptide, saponin derivatives,mycobacterium cell wall preparations, monophosphoryl lipid A, mycolicacid derivatives, nonionic block copolymer surfactants, Quil A, choleratoxin B subunit, polyphosphazene and derivatives, and immunostimulatingcomplexes (ISCOMs) such as those described by Takahashi et al. (1990)Nature 344:873-875. For veterinary use and for production of antibodiesin animals, mitogenic components of Freund's adjuvant can be used. Aswith all immunogenic compositions, the immunologically effective amountsof the immunogens must be determined empirically. Factors to beconsidered include the immunogenicity, whether or not the immunogen willbe complexed with or covalently attached to an adjuvant or carrierprotein or other carrier, route of administration and the number ofimmunizing doses to be administered. Such factors are known in thevaccine art and it is well within the skill of immunologists to makesuch determinations without undue experimentation.

[0035] The present invention encompasses compositions and methods ofmaking the compositions. Although singular forms may be used, more thanone polyol, more than one biological substance and more than oneinhibitor of the Maillard reaction may be present. Determination of theeffective amounts of these compounds is within the skill of one in theart.

[0036] As used herein, the term “carbohydrates” includes, but is notlimited to, monosaccharides, disaccharides, trisaccharides,oligosaccharides and their corresponding sugar alcohols, polyhydroxycompounds such as carbohydrate derivatives and chemically modifiedcarbohydrates, hydroxymethyl starch and sugar copolymers (Ficoll). Bothnatural and synthetic carbohydrates are suitable for use herein.Synthetic carbohydrates include, but are not limited to, those whichhave the glycosidic bond replaced by a thiol or carbon bond. Both D andL forms of the carbohydrates may be used. The carbohydrate may benon-reducing or reducing. Suitable stabilizing polyols are those inwhich a bioactive material can be dried and stored without losses inactivity by denaturation, aggregation or other mechanisms. Prevention oflosses of activity can be enhanced by the addition of various additivessuch as inhibitors of the Maillard reaction as described below. Additionof such inhibitors is particularly preferred in conjunction withreducing carbohydrates.

[0037] Reducing carbohydrates suitable for use in the present inventionare those known in the art and include, but are not limited to, glucose,maltose, lactose, fructose, galactose, mannose, maltulose, iso-maltuloseand lactulose.

[0038] Non-reducing carbohydrates include, but are not limited to,non-reducing glycosides of polyhydroxy compounds selected from sugaralcohols and other straight chain polyalcohols. Other usefulcarbohydrates include raffinose, stachyose, melezitose, dextran, sucroseand sugar alcohols. The sugar alcohol glycosides are preferablymonoglycosides, in particular the compounds obtained by reduction ofdisaccharides such as lactose, maltose, lactulose and maltulose. Theglycosidic group is preferably a glucoside or a galactoside and thesugar alcohol is preferably sorbitol (glucitol). Particularly preferredcarbohydrates are maltitol (4-O-β-D-glucopyranosyl-D-glucitol), lactitol(4-O-β-D-galactopyranosyl-D-glucitol), iso-maltulose, palatinit (amixture of GPS, α-D-glucopyranosyl-1-6-sorbitol and GPM), andα-D-glucopyranosyl-1-6-mannitol, and its individual sugar alcohols,components GPS and GPM.

[0039] Preferably, the stabilizing polyol is a carbohydrate that existsas a hydrate, including trehalose, lactitol and palatinit. Mostpreferably, the stabilizing polyol is trehalose. It has now been foundthat, surprisingly, solid dose compositions containing sugar hydrateslike trehalose lack the “stickiness” or “tackiness” of solid dose formscontaining other carbohydrates. Thus, for manufacture, packaging andadministration, trehalose is the preferred carbohydrate. Trehalose,α-D-glucopyranosyl-α-D-glucopyranoside, is a naturally occurring,non-reducing disaccharide which was initially found to be associatedwith the prevention of desiccation damage in certain plants and animalswhich can dry out without damage and can revive when rehydrated.Trehalose has been shown to be useful in preventing denaturation ofproteins, viruses and foodstuffs during desiccation. See U.S. Pat. Nos.4,891,319; 5,149,653; 5,026,566; Blakeley et al. (1990) Lancet336:854-855; Roser (July 1991) Trends in Food Sci. and Tech. 166-169;Colaco et al. (1992) Biotechnol. Internat., 345-350; Roser (1991)BioPharm. 4:47-53; Colaco et al. (1992) Bio/Tech. 10:1007-1011; andRoser et al. (May 1993) New Scientist, pp. 2.5-28.

[0040] It has also now been found, surprisingly, that the glasstransition temperature (Tg) of trehalose can be elevated by the additionof glass modifiers. Preferably the glass modifiers are proteins thatcomprise 0.002-50% of the glass modifier-trehalose mixture. Thus, thepresent invention encompasses the compositions and methods of making thecompositions comprised of trehalose and at least one modifier, whereinthe compositions have Tgs equal to or greater than the same compositeglasses of pure trehalose. Suitable active glass modifiers include, butare not limited to, proteins and other hydrated macromolecules. Suitableproteins include any physiologically acceptable protein and may be inertor a protein to be delivered therapeutically, i.e. a bioactive material.

[0041] It has also been found that bioactive materials soluble only inorganic solvents can be dried in trehalose from an organic/aqueoussolvent to give a conformation that is now soluble in aqueous solvents.Methods of making the dried material and compositions obtained therebyare provided by the invention. The bioactive material is dissolved in anorganic/aqueous solvent in combination with an effective amount oftrehalose and then dried. This gives a solid solution of the bioactivematerial in a trehalose glass which then readily dissolves in an aqueoussolution to give an aqueous suspension of the insoluble bioactivematerial. It has now been shown that the immunosuppressant cyclosporin A(which is insoluble in water and normally administered as an oilemulsion) in a solution of trehalose in a 1:1 ethanol:water mixture canbe dried to give a clear glass of trehalose containing cyclosporin A.This glass can be milled to give a free flowing powder which if added towater dissolves instantaneously to give a suspension of cyclosporin A inwater. If the solution dried contained a mixture of trehalose/trehaloseoctaacetate (insoluble in water), then the glass formed can be tailoredfor different dissolution rates by varying the ratio of the two.

[0042] Preferably, the compositions contain an amount of at least onephysiologically acceptable salt which effects a loss of water from thecomposition so that at ambient humidity the vapor pressure of water ofcrystallization is at least 14 mm Hg (2000 Pa) at 20° C. (molecularwater-pump buffer, hereinafter referred to as “MWPB”) and does notinterfere with glass formation of the stabilizing polyol. In the case ofpowders for pulmonary administration, addition of an effective amount ofMWPBS is particularly preferred as they have been found to preventwetting and clumping. An effective amount of an MWPB is one whichsubstantially prevents wetting and clumping. Suitable salts are thosedescribed in Spanish pat. no. 2009704. These may constitute a buffersystem or may replace a substantial amount of a component of the bufferin a conventional formulation. Suitable salts include, but are notlimited to, ammonium chloride, orthophosphate and sulfate; bariumchloride dihydrate; calcium lactate pentahydrate; copper sulfatepentahydrate; magnesium salicylate tetrahydrate, magnesium sulfateheptahydrate; potassium bisulfate, bromide, chromate and dihydrogenorthophosphate; sodium acetate trihydrate, bromoiridate dodecahydrate,carbonate decahydrate, fluoride, hydrogen orthophosphate dodecahydrate,metaperiodate trihydrate, metaphosphate trihydrate and hexahydrate,sulfite heptahydrate, sulfate heptahydrate and decahydrate andthiosulfate pentahydrate; and zinc sulfate heptahydrate and combinationsthereof.

[0043] Preferably, if the bioactive material and/or glass forming polyolcontain carboxyl and amino, imino or guanidino groups, the compositionsfurther contain at least one physiologically acceptable inhibitor of theMaillard reaction in an amount effective to substantially preventcondensation of amino groups and reactive carbonyl groups in thecomposition.

[0044] The inhibitor of the Maillard reaction can be any known in theart. The inhibitor is present in an amount sufficient to prevent, orsubstantially prevent, condensation of amino groups and reactivecarbonyl groups. Typically, the amino groups are present on thebioactive material and the carbonyl groups are present on thecarbohydrate, or the converse. However, the amino and carbonyl groupsmay be intramolecular within either the biological substance or thecarbohydrate. Various classes of compounds are known to exhibit aninhibiting effect on the Maillard reaction and hence to be of use in thecompositions described herein. These compounds are generally eithercompetitive or noncompetitive inhibitors. Competitive inhibitorsinclude, but are not limited to, amino acid residues (both D and L),combinations of amino acid residues and peptides. Particularly preferredare lysine, arginine, histidine and tryptophan. Lysine and arginine arethe most effective. There are many known noncompetitive inhibitors.These include, but are not limited to, aminoguanidine and derivativesand amphotericin B. EP-A-O 433 679 also describes suitable Maillardinhibitors which are 4-hydroxy-5,8-dioxoquinoline derivatives.

[0045] As discussed below, the composition may further contain at leastone physiologically acceptable glass. Suitable glasses include, but arenot limited to, carboxylate, nitrate, sulfate, bisulfate, carbohydratederivatives and combinations thereof. Carboxylate and carbohydratederivatives are preferred where water soluble glasses are required asmany of these derivatives are slowly soluble in water. Suitable glassesinclude, but are not limited to, those described in PCT/GB 90/00497.

[0046] The composition may also be coated with one or more layers of aphosphate glass having a predetermined solution rate. The compositionmay further contain other water soluble and biodegradable glass formers.Suitable glass formers include, but are not limited to, lactide andlactide/glycolide copolymers, glucuronide polymers and other polyesters,polyorthoesters, and polyanhydrides.

[0047] In one embodiment, the delivery vehicle of the invention is sizedand shaped for penetration of the epidermis and is suitable forballistic delivery. Suitable vehicle size is thus on the order ofmicrons, preferably in the range of 1-5 microns in diameter and 5-150microns in length, which allows penetration and delivery through theepidermis to subcutaneous and intradermal tissues. It will beappreciated that, at this size, the delivery vehicle may macroscopicallyappear to be in powder form, regardless of its configuration at themicroscopic level.

[0048] Preferred configurations of the delivery vehicle of the inventionare microneedles and microfibers of a stabilizing polyol glass. Themanufacture of microfibers is relatively simple and economical andresults in stable delivery vehicles comprised of the stabilizing polyoland the bioactive material. Additional stabilizers, buffers, glasses andpolymers may also be added as described herein. Many of the most labilebiomolecules can withstand high temperatures (e.g., 60-100° C.) whenstabilized by drying in trehalose, provided that the majority of theirsurface is in contact with the stabilizing polyol. Temperatures of 70°C. can be tolerated for over a month (Colaco et al. (1992)Bio/Technology 10:1007-1011) and higher temperatures for shorterperiods. The results presented herein show that the fluorescent proteinphycoerythrin dried in trehalose can be stored at 100° C. for at leastone month with no detectable loss of functional activity. Otherstabilizing polyols give protection at lower temperatures thantrehalose. The maximum temperature of protection must be determinedempirically and is within the skill of one in the art without undueexperimentation.

[0049] Providing the exposure time is limited, bioactive materialsadmixed in dry stabilizing polyols can be heated to fluidize the glasswhich can then be drawn or spun as a fiber without damage to theproduct. Fibers can either be drawn from a billet and wound onto a drumor they can be spun through fine holes in a rapidly rotating cylinderthat is heated above the melting point of the glass. Being inherentlybrittle, these glass fibers can be readily crushed or chopped into shortlengths to form long cylindrical rods or needles. By varying thediameter of the fibers produced, needles can be formed which vary frommicro to macro needles, i.e., from thicknesses of a few microns tofractions of a millimeter. It has been found that cotton candy machinesare suitable for use in preparing the microfibers. Although the optimalconditions must be determined empirically for each stabilizing polyol,such determinations are well within the skill of one in the art.

[0050] The microfibers prepared in accord with the principles of thepresent invention, have a relatively high aspect ratio, i.e., lengthcompared to diameter, preferably in the range of 1-5 microns in diameterand 5-150 microns in length. This high aspect ratio provides forenhanced “end on” penetration upon ballistic delivery, by the tendencyof the microfibers to lineup parallel to the barrel of the ballisticmicroinjector, described in more detail below. Longer macrofibers may beinjected using conventional impact ballistic devices or by trocar.

[0051] Alternative preferred embodiments of the delivery vehicle includeuniform microspheres, preferably with a narrow size distribution. Thisconfiguration is particularly useful when increased control of the depthof penetration of the delivery vehicle is desirable. Such control wouldbe useful, for example, for intradermal delivery of vaccines to thebasal layer of the epidermis, to bring antigen into proximity to theLangerhans cells of the skin to induce optimal immune responses.

[0052] To prepare microspheres of the present invention, several methodscan be employed depending upon the desired application of the deliveryvehicles. Suitable methods include, but are not limited to, spraydrying, freeze drying, air drying, vacuum drying, fluidized-bed drying,milling, co-precipitation and critical fluid extraction. In the case ofspray drying, freeze drying, air drying, vacuum drying, fluidized-beddrying and critical fluid extraction; the components (stabilizingpolyol, bioactive material, buffers etc.) are first dissolved orsuspended in aqueous conditions. In the case of milling, the componentsare mixed in the dried form and milled by any method known in the art.In the case of co-precipitation, the components are mixed in organicconditions and processed as described below. Spray drying can be used toload the stabilizing polyol with the bioactive material. The componentsare mixed under aqueous conditions and dried using precision nozzles toproduce extremely uniform droplets in a drying chamber. Suitable spraydrying machines include, but are not limited to, Buchi, NIRO, APV andLab-plant spray driers used according to the manufacturer'sinstructions. A number of carbohydrates are unsuitable for use in spraydrying as the melting points of the carbohydrates are too low causingthe dried materials to adhere to the sides of the drying chamber.Generally, carbohydrates with a melting point of less than the spraydrying chamber are unsuitable for use in spray drying. For example,palatinit and lactitol are not suitable for use in spray drying underconventional conditions. A determination of suitable carbohydrates canthus be made on known melting points or determined empirically. Suchdeterminations are within the skill of one in the art.

[0053] An alternative method for manufacturing microspheres as deliveryvehicles in accord with the present invention is to prepare a uniformaqueous/organic phase emulsion of the bioactive material in a solutionof the stabilizing polyol as the aqueous phase and the glass former inthe organic phase. This is followed by drying of the emulsion dropletsto form a solid solution of the bioactive material and stabilizingpolyol in an amorphous matrix of the glass former. In a modification ofthis method, the emulsion may be formed from the bioactive compound insolid solution in the stabilizing polyol and two different polymersdissolved together in one solvent, or dissolved into two separatesolvents. The solvent(s) are then removed by evaporation to yield doubleor multi-walled microspheres. Suitable methods for making multi-walledmicrospheres are described, for instance, in Pekarek et al. (1994)Nature 367:258-260; and U.S. Pat. No. 4,861,627.

[0054] The bioactive material can also be dried from an organic solutionof the stabilizing polyol and the bioactive material to form a glasscontaining homogeneously distributed bioactive material in solidsolution in the polyol glass. These glasses can then be milled and/ormicronized to give microparticles of homogeneous defined sized.

[0055] The bioactive material and the stabilizing polyol can also beco-precipitated to give high quality powders. Co-precipitation isperformed by spraying, for instance with an air brush, the bioactivematerial and stabilizing polyol and/or glass former into a liquid inwhich neither dissolves, such as ice-cold acetone.

[0056] The invention also encompasses hollow fibers for delivery ofbioactive materials. By drawing down a heated hollow billet, fine hollowneedles can be formed. These can be made to contain a finely powderedstabilized compound by introduction of the fine powder during themelting and drawing down process. The hollow fiber can also be made ofthermoplastic, organic polymer and/or carbohydrate and/or derivatizedcarbohydrate glass which may itself be water soluble or biodegradable.

[0057] An alternative embodiment of the delivery vehicle in theinvention comprises a hollow vehicle comprised of water soluble glass orplastic which is filled and optionally coated with stabilizing polyolglass and the bioactive material. Fine hollow fibers of water-solubleinorganic or organic glasses can be drawn from a hollow billet and afinely powdered stabilizing polyol-bioactive material can beincorporated into the lumen of the billet, and therefore of the fiber,during the process. Alternatively, hollow needles of these glasses maybe filled by allowing capillarity to draw up suspensions of the finelypowdered bioactive substance in a volatile organic solvent which issubsequently removed by evaporation leaving the needle filled with thebioactive substance. In a modification of this method, incorporation ofa soluble glass former in the organic solvent phase will result in theneedle being filled with the bioactive substance in solid solution inthe glass former.

[0058] In another embodiment of the invention, coformulations ofstabilizing polyol glass and other water soluble materials are included.For example, coformulations of stabilizing polyol glass withwater-soluble glasses such as phosphate glasses (Pilkington GlassCompany) or biodegradable plastics such as lactide or lactide/glycolidecopolymers will yield a more slowly eroding vehicle for delayed releaseof the bioactive material. A finely powdered stabilizing polyolglass/bioactive material can be intimately mixed with a finely powderedcarboxylate glass and co-sintered. Alternatively, if a metal carboxylateglass has a lower melting point than the stabilized bioactive polyolglass, the latter can be homogeneously embedded as a solution in acarboxylate glass by cooling the melt obtained. This can be milled togive a fine powder with solubilities intermediate between the rapidsolubility of the stabilizing polyol and the slow solubility of thecarboxylate glass.

[0059] Alternate coformulations include the use of a homogeneoussuspension of the finely powdered bioactive material/stabilizing polyolmixture encapsulated in a carboxylate glass by drying from an organicsolution of the carboxylate to form the carboxylate glass. This can beground to give a fine powder which would have the rapidly dissolvingstabilizing polyol glass containing the encapsulated bioactive materialentrapped within a slow dissolving carboxylate glass (i.e., aconventional slow-release system). Pulsatile release formats can beachieved either by repeated encapsulation cycles using glasses ofdifferent dissolution rates, or by mixing powders of a number ofcoformulations with the desired range of release characteristics. Notethat this glass could also be drawn or spun to give microfibers ormicroneedles which would be slow-release implants. It will beappreciated that any stabilizing polyol formulation should be such thatit is capable of releasing the bioactive material upon administration,and should not unduly effect the stability of the material beingadministered.

[0060] As discussed above, glasses of derivatized carbohydrates are alsosuitable for use herein. Suitable derivatized carbohydrates include, butare not limited to, carbohydrate esters, ethers, imides and other poorlywater-soluble derivatives and polymers.

[0061] The delivery vehicle is loaded with the bioactive materials to bedelivered to the tissue by drying a solution of the bioactive materialcontaining a sufficient quantity of stabilizing polyol to form a glasson drying. This drying can be accomplished by any method known in theart, including, but not limited to, freeze drying, vacuum, spray, belt,air or fluidized-bed drying. The dried material can be milled to a finepowder before further processing the material with the polyol glass orcoformulation.

[0062] Different dosing schemes can also be achieved depending on thedelivery vehicle employed. A stabilizing polyol glass delivery vehicleof the invention can provide for a quick release or flooding dose of thebioactive material after administration, upon the dissolving and releaseof the bioactive material from the stabilizing polyol glass.Coformulations of stabilizing polyol with water soluble glasses andplastics such as phosphate, nitrate or carboxylate glasses andlactide/glycolide, glucuronide or polyhydroxybutyrate plastics andpolyesters, can provide more slowly dissolving vehicles for a slowerrelease and prolonged dosing effect. A booster effect can also berealized by utilizing a hollow water soluble vehicle filled and coatedwith a stabilizing polyol glass loaded with the bioactive material. Thepolyol glass coating loaded with the material will dissolve rapidly togive an initial dosing effect. While the hollow outer portion of thevehicle dissolves, there will be no dosing action, followed by a boostereffect of the inner filling comprised of a stabilizing polyol and abioactive material when the hollow outer portion is breached bydissolution. Such pulsatile release format is particularly useful forvaccine delivery. Should multiple effect pulsatile delivery bedesirable, delivery vehicles with any combination of layers of watersoluble “non-loaded” materials and stabilizing polyol glass loaded withthe bioactive material can be constructed.

[0063] The delivery of more than one bioactive material can also beachieved using a delivery vehicle comprised of multiple coatings orlayers of the stabilizing polyol loaded with different materials ormixtures thereof. Administration of the solid dose delivery vehicle ofthe present invention can be used in conjunction with other conventionaltherapies and coadministered with other therapeutic, prophylactic ordiagnostic substances.

[0064] The invention further encompasses methods of delivery. Suitabledelivery methods include, but are not limited to, topical, transdermal,transmucosal, oral, gastrointestinal, subcutaneous, ocular, andby-inhalation (naso-pharyngeal and pulmonary, including transbronchialand transalveolar). Topical administration is, for instance, by adressing or bandage having dispersed therein the stabilizing polyolglass/bioactive material, or by direct administration into incisions oropen wounds. Creams or ointments having dispersed therein slow releasebeads of bioactive material/stabilizing polyol are suitable for use astopical ointments or wound filling agents.

[0065] Compositions for transdermal administration are preferablypowders of microneedles or microbeads. Larger, macroscopic needles andbeads are also provided for subdermal implantation and extended drugdelivery. The particle sizes should be small enough so that they do notcause skin damage upon administration. Preferably, the powders aremicroneedles of approximately 10-1,000 microns in length and 1-150microns in diameter. The powders may be prepackaged in single-dose,sealed, sterile formats. Suitable methods of transdermal administrationinclude, but are not limited to, ballistic, trocar and liquid jetdelivery. Ballistic administration is preferred as it is relativelypainless. Generally the delivery vehicle is accelerated in a shock waveof helium or another gas and fired into the epidermis. A suitable devicefor ballistic delivery is described in PCT/GB 94/00753. A suitabledevice for liquid-jet delivery is a Medi-ject device (Diabetes Care(1993) 1b, 1479-1484). Such liquid-jet devices are particularly usefulwith the larger macroneedle delivery vehicles which may also bedelivered by the use of conventional impact ballistic devices or bytrocar.

[0066] Upon transdermal administration, the degree of penetration of thedelivery vehicle can be controlled to a certain degree, not only by theballistic microinjector, described below, but also the shape and size ofthe powder particles. For example, when a relatively uniform and lesserdegree of penetration is desirable, microspheres may be more suitablefor the practice of the present invention. When a greater degree ofpenetration is desirable, a microfiber configuration may be preferred.Because the aspect ratio (i.e., length to diameter) of the microneedlesis high they have higher masses than spherical particles with a similardiameter. If they can be induced to impact with the skin “end-on,” theirhigher mass will give them a higher momentum for the same velocity andthey will thus penetrate deeper into the tissues. When randomlyorientated microneedles are put into a laminar flow of gas, they willalign themselves in the direction of the air flow and in thegas-propelled ballistic injector this will ensure that they impact theskin at the right angles and thus penetrate it.

[0067] The compositions suitable for transmucosal delivery include, butare not limited to, lozenges for oral delivery, pessaries, and rings andother devices for vagina or cervical delivery.

[0068] Compositions suitable for gastrointestinal administrationinclude, but are not limited to, pharmaceutically acceptable powders andpills for ingestion and suppositories for rectal administration.

[0069] Compositions suitable for subcutaneous administration include,but are not limited to, various implants. Preferably the implants aremacroscopic spherical or cylindrical shapes for ease of insertion andmay be either fast or slow release. Since the entire implant isdissolved in the body fluids, removal of the implant is not necessary.Furthermore, the implants do not contain synthetic polymers and thus areless likely to initiate a separate immune response.

[0070] Compositions suitable for ocular administration include, but arenot limited to microsphere and macrosphere formulations, and salinedrops.

[0071] Compositions suitable for by-inhalation administration include,but are not limited to, powders of bioactive material/stabilizingpolyol. Preferably the powders are of a particle size 0.1 to 10 microns.More preferably, the particle size is 0.5 to 5 microns. Most preferably,particle size is 1 to 4 microns. In particular for pulmonaryadministration, the preferred particle size is 2.5-3 microns. Preferablythe powders also contain an effective amount of a physiologicallyacceptable MWPB. An effective amount of an MWPB is one whichsufficiently reduces wetting to prevent substantial clumping, forinstance, a 50% molar ratio of potassium sulfate. Sodium sulfate andcalcium lactate are the preferred salts with potassium sulfate being themost preferred. Atomizers and vaporizers filled with the powders arealso encompassed by the invention.

[0072] There are a variety of devices suitable for use in by-inhalationdelivery of powders. See, e.g., Lindberg (1993) Summary of Lecture atManagement Forum 6-7 Dec. 1993 “Creating the Future for PortableInhalers.” Additional devices suitable for use herein include, but arenot limited to, those described in WO9413271, WO9408552, WO9309832 andU.S. Pat. No. 5,239,993.

[0073] The following examples are provided to illustrate but not limitthe present invention.

EXAMPLE 1 Methods of Making Solid Dose Delivery Vehicles

[0074] a) Carbohydrate Glass Microfiber Formation.

[0075] Glasses were formed by drying 20% solutions of either trehalose,lactitol, palatinit or GPS, containing MWPB and 1 mg/ml of thefluorescent algal protein phycoerythrin under vacuum (80 mTorr) for 16hrs. The glasses were ground in a domestic coffee mill to yield a coarsepowder which was used to fill the spinning head of a Kando K1 KandyFloss cotton candy machine (GB Patent No. 00103/76). The motor was thenswitched on and the powdered sugar glass heated at element settingsbetween 5 and 9. Residence time in the spinning head was 2-10 min and acontinuous process was maintained by constantly topping up the head.

[0076] The fibers produced were ground in a domestic coffee grinder andthe results obtained are presented in Table 1 which shows an average ofthe needles produced. These data indicate that, with all three sugarglasses, reduced element settings result in the production of finerdiameter microneedles. With trehalose, setting 6 gave microneedles witha mean diameter of 15 microns, and setting 9, microneedles with a meandiameter of 40 microns. With GPS, setting 9 gave microneedles with amean diameter of 15 microns. Microneedles formed from glasses containingbuffer salts remained dry at ambient temperatures and humidities.Microneedles containing phycoerythrin showed retention of biologicalactivity as assessed by fluorescence. TABLE 1 Microneedle size analysisLength (μm) Width (μm) Mean 192.60 43.35 Standard Error 12.53 2.33Median 167.5 37.5 Mode 137.5 47.5 Standard Deviation 123.44 22.91 SampleVariance 15237.75 524.72 Kurtosis 16.17 2.55 Skewness 3.35 1.45 Range862.5 115 Minimum 67.5 10 Maximum 930 125 Sum 18682.5 4205 Count 97 97Confidence Level (95.000%) 24.57 4.56

[0077] b) Binary Carbohydrate/organic Mixture Glass MicrofiberFormation.

[0078] Glasses were formed by drying a 5:1:1 mixture of trehalose,sodium octanoate and water under vacuum (80 mTorr) for 16 hrs. Theglasses were ground in a domestic coffee mill to yield a coarse powderwhich was used to fill the spinning head of a Kando K1 Kandy Flossmachine. The motor was then switched on and the powdered binarycarbohydrate/organic glass heated at element settings between 5 and 9.As with pure trehalose glasses, reduced element settings resulted in theproduction of finer diameter microneedles. The binary mixture glassescan be tailored to yield glasses with significantly different tensileproperties compared to the corresponding pure trehalose glasses.Residence time in the spinning head was again 2-10 min and a continuousprocess was maintained by constantly topping up the head. The resultsobtained indicate that variations of the melting points and dissolutiontimes of the glasses and the resulting physical properties of themicrofibers can be achieved by varying both the carbohydrate/organicmolecules and ratios used.

EXAMPLE 2 Methods of Making Solid Dose Delivery Vehicles

[0079] a) Micronized Powder Preparation.

[0080] Glasses were formed by drying 20% solutions of either trehalose,lactitol, palatinit, GPM or GPS, containing an equimolar ratio of MWPBand protein, by freeze-drying under vacuum (80 mTorr) for 16 hrs. Theglasses were powdered using a Trost air-jet mill. Particle size in themicronized powders were measured using a Malvern Mastersizer laserparticle sizer. The results obtained with micronized powders obtainedfrom an original solution of 0.5 M trehalose and 0.5 M calcium lactateshowed a monodisperse particle distribution with mean particle diametersof 1.1 microns (FIG. 1). The powders containing MWPB remained afree-flowing powder and showed no change in particle size or clumpingand uptake of water on extended exposure to ambient temperatures andhumidities (FIGS. 2A and 2B).

[0081] b) Spray-dried Powder Preparation.

[0082] 20% solutions of trehalose containing MWPB salts and protein(phycoerythrin) were dried in a Buchi or Lab-Plant spray drier at a pumpspeed of 500-550 ml/hr and an inlet temperature of 180° C. Particle sizewas again measured using a SympaTec laser particle sizer. Thespray-dried powders showed a monodisperse particle distribution with asufficiently narrow peak size distribution for effective use asparticles in a powder ballistic device. In the results shown in FIG. 3,particle size analysis of a spray-dried powder produced by spray dryinga mixture of 0.5 M trehalose and 0.5 M calcium lactate on a Lab-Plantspray drier showed a mean particle diameter of 8.55 microns andillustrates the tight peak distribution obtained. Variation of the meanparticle size can be achieved by varying either the composition of themixture to be spray dried or the characteristics of the spray driernozzle assembly used. The results shown in FIG. 4 provide a comparisonof the particle size analysis of the spray-dried powder as in FIG. 3with a spray-dried powder produced by drying the same mixture on theBuchi spray drier which uses a different nozzle assembly. The peakdistribution shown in FIG. 4 shows an equally narrow range but the meanparticle size is now 7.55 microns. These data show that the particlesobtained by different spray-drying processes are equally suitable toprovide compositions for ballistic delivery. Note that the ability tovary particle size results in compositions with different penetrativecharacteristics. This is particularly important for determiningintradermal or intramuscular delivery as the penetration is a functionof particle momentum and the distribution is a function of the scatterof particle size.

[0083] c) Drying from Organic Solvents

[0084] A 50 mg/ml solution of cyclosporin A in a 1.1 mixture ofethanol:water, containing 20% trehalose, was air-dried at ambienttemperature to form a clear trehalose glass containing cyclosporin A insolid solution. The glass was ground to give a powder, according to themethod described in Example 1, and remained a free-flowing powder atambient temperature and humidities. Addition of the powder to waterresulted in the dissolution of the trehalose and the formation of auniform aqueous suspension of cyclosporin A.

[0085] d) Co-precipitation Powder Preparation

[0086] 20% solutions of trehalose, lactitol, palatinit, GPM or GPS,containing MWPB and protein (phycoerythrin) were dried by spraying intoan acetone-solid carbon dioxide freezing bath. The precipitated powderswere separated by centrifugation or filtration and air dried to removeresidual solvent. The powders again showed a monodisperse particledistribution and those containing buffer formulation salts remained dryat ambient temperatures and humidities.

EXAMPLE 3 Variable Solubility of Classes of Carbohydrate/carbohydrateEster Coformulations

[0087] Various ratios of trehalose and trehalose octaacetate (TOAC) ortwo different carbohydrate esters were dissolved in pyridine withsufficient water added to give a clear solution. The solutions weredried rapidly to give clear transparent monophasic glasses of thecarbohydrate and/or carbohydrate ester mixes. TOAC is almost insolublein water and increased amounts of the ester in the mixture resulted inthe increased dissolution times of the coformulated glass formed.

[0088] Coformulations of TOAC and raffinose undecaacetate containing1-2% Mordant Blue (MB9) dye were prepared as described above. Therelease rates of MB9 were measured by absorbance quantitatedspectrophotometrically and the results are depicted in FIG. 5. Theseresults indicate that glasses of two carbohydrate derivatives providedifferent release characteristics and that the use of two or morecarbohydrate derivatives results in glasses tailored to provide desiredrelease characteristics.

EXAMPLE 4 Protection of Proteins Against an Organic Solvent and ElevatedTemperatures Effected by Drying in Trehalose

[0089] a) Protection of Horseradish Peroxidase and Alkaline PhosphataseAgainst Acetone Effected by Drying in Trehalose

[0090] A 0.1 mg/ml horseradish peroxidase solution or a 1 mg/ml alkalinephosphatase/4 mg/ml bovine serum albumin solution was dried in an FTSSystems freeze drier with or without 50% trehalose. The drier was usedas a vacuum drier and the mixtures dried without freezing. Four timesthe volume of solvent was added and the solution was allowed toevaporate to dryness. The contents were redissolved in 5 milliliters ofwater, and enzyme activity was assessed, in serial dilution, bycommercial ‘kit’ reagents. The alkaline phosphatase kit was obtainedfrom Sigma Chemical Co. and the horseradish peroxidase kit was obtainedfrom Kirkegaard & Perry Laboratories, Inc. As shown in FIGS. 6A and 6B,the enzymes dried with trehalose were more resistant to acetone than theenzymes dried without trehalose.

[0091] b) Protection of Phycoerythrin Against Organic Solvents Affordedby Drying in Trehalose

[0092] A 400 μg/ml phycoerythrin solution was freeze-dried in a Labconcofreeze-drier with or without 20% trehalose. The dried protein powder wasexposed to a number of organic solvents for 72 hrs. The phycoerythrinremained fluorescent in acetone, acetonitrile chloroform and methanol.In pyridine, the phycoerythrin retained fluorescent for 24-48 hr butbegan wetting and lost fluorescence by 72 hrs. In dimethylsulfoxide, thepowder solubilized but the phycoerythrin remained fluorescent.

[0093] c) Protection of Phycoerythrin Against 100° C. Afforded by Dryingin Trehalose

[0094] A 400 μg/ml phycoerythrin solution was freeze-dried in the FTSdrier with or without 20% trehalose. The dried protein was stored at1000 for one month with no loss of functional activity.

[0095] d) Effect of Protein on Tg of Trehalose

[0096] The presence of protein in a powdered trehalose glass has nowbeen found to stabilize the glass against the plasticizing effected bywater on pure trehalose glasses. This is illustrated by the resultsdepicted in FIG. 7, which show the effect of water on the glasstransition temperature of trehalose glasses with (solid line) or without(broken line) bovine serum albumin at concentrations of from 0.002-50%.This effect is not seen or is seen only partially with othercarbohydrates, as illustrated by the results depicted in FIG. 8utilizing maltose.

[0097] This elevation of Tg by protein is utilized to formulatetrehalose stabilized protein in a pure trehalose glass. A powderedprotein-containing trehalose glass is prepared as described in Example1, added to the melt of a pure trehalose glass and the mixtureimmediately quenched to give the trehalose-stabilized protein powder ina solid solution in a pure trehalose glass. This glass can then befurther processed as described in Examples 1 and 2. A similar embeddedglass can be formed if an alternative stabilizing polyol with a Tg lowerthan that of trehalose is used to form the pure sugar glass, which againallows this glass to be melted and used below the melting point of thepowdered, stabilized-protein glass to be embedded. For example,palatinit glasses melt at 60-70° C. at which temperature theprotein-stabilized powder is still a glass and the trehalose-stabilizedprotein glass can thus be encapsulated in the palatinit glass melt bysimply mixing and quenching.

EXAMPLE 5 Preparation of Bioactive Material/stabilizing PolyolCompositions

[0098] a) Microparticles of trehalose containing MB9 were prepared byspray drying as described in Example 2b. The solution dried contained0.39 M trehalose and 0.14 M calcium lactate and 0.5% MB9. Theseparticles were coated by adding them to a saturated solution of zincpalmitate (ZnCl₁₆) in toluene and cooling from 60° C. to 30° C. Thisdeposited a layer of ZnCl₁₆ on the particles which were then filteredunder pressure to remove the excess ZnCl₁₆, washed with acetone andair-dried. The resulting powder remained unwetted in water for at leastthree days (the particles floated in the water without sinking orreleasing MB9 and thereafter slowly released dye into the water). Thus,otherwise water soluble powders may be made water impermeable by coatingwith metal carboxylates such as ZnCl₁₆ to yield slow release formats.Note that the coating material is most likely in crystalline form andnot a glass; therefore, the solid phase in which the bioactive materialsare suspended need not be in the glass phase to be impermeable.

[0099] b) Coformulation of Carbohydrate and Organic Glasses byEvaporation

[0100] A powdered trehalose glass containing phycoerythrin was added toa 1:1 mixture of sodium octanoate and zinc ethylhexanoate dissolved inan excess of chloroform and evaporated under a stream of N₂ at roomtemperature to yield a carboxylate glass containing phycoerythrin powderin solid solution. The coformulated glass remained insoluble in waterfor at least 48 hrs. The phycoerythrin powder remained fluorescent bothin the initial organic solution and in the final glass.

[0101] c) Coformulation of Carbohydrate and Organic Glasses byCo-melting

[0102] A preformed organic glass formed by quenching a melt of 1:1mixture of sodium octanoate and zinc ethylhexanoate was melted at 95° C.and a powdered trehalose glass containing phycoerythrin was added to themelt. The resultant mixture was immediately quenched on an aluminumblock precooked to 15° C. A clear carboxylate glass formed containingencapsulated phycoerythrin powder which retained its biologicalfunctionality as assayed by its ability to fluoresce. Varying the natureand ratios of the carbohydrate and organic moieties in the coformulatedglasses results in glasses with a range of slow-release characteristicsas assessed from their variable dissolution times in water.

[0103] d) Coformulation of Carbohydrate Glasses and Plastics byEvaporation

[0104] A powdered trehalose glass containing phycoerythrin-preparedaccording to Example 1 was added to a solution of perspex filingsdissolved in an excess of chloroform and evaporated under a stream of N₂at room temperature to yield a solid perspex block containing thephycoerythrin powder in solid solution. The phycoerythrin powderremained fluorescent both in the initial organic solution and in thereformed solid perspex which was impermeable to water even after 4weeks. Similar results were obtained with polyester dissolved indichloromethane and polyurethane dissolved in dimethylsulfoxide.

EXAMPLE 6 Preparation of Hollow Needles Filled with Bioactive Materials

[0105] The end of a billet of a trehalose glass tubes with a centralcavity filled with a powdered trehalose glass containing phycoerythrinprepared according to Example 1 was melted in a zone furnace and thefiber drawn by winding onto a metal drum rotated at constant speed. Thehollow fibers formed contain the finely powdered trehalose-stabilizedcompound and can be cut to any desired size. The hollow fiber can alsobe made of thermoplastic, organic glass or carbohydrate which may itselfbe water soluble, and by varying the diameter of the fibers produced,the filled needles can be formed which vary from micro to macro needles,i.e. from thicknesses of microns to fractions of a millimeter. thehollow needles may be filled with any solid dose vehicle describedherein.

EXAMPLE 7 Ballistic Delivery of Solid Dosage Delivery Vehicle

[0106] Powdered glasses were injected into the skin by propulsion athypersonic speeds using a pressure Shock wave created by the release ofcompressed gas. The powder was held in the chamber attached to the largeend of a funnel-shaped cavity to the smaller end of which was attached acartridge of compressed gas sealed by a mylar film and the hypersonicshock wave was generated by rupture of the mylar membrane.Alternatively, a timer relay-driven solenoid can be used to control thehelium release which would allow functioning at lower helium pressures.This is the principle used in the particle inflow gun (PIG) developed byFiner for transforming plant tissues. Vain et al. (1993) Plant CellTissue and Organ Culture 33:237-246.

[0107] Although the foregoing invention has been described in somedetail by way of illustration and example for purposes of clarity ofunderstanding, it will be apparent to those skilled in the art thatcertain changes and modifications may be practiced. Therefore, thedescription and examples should not be construed as limiting the scopeof the invention, which is delineated by the appended claims.

1-14. (cancel).
 15. A therapeutic dried composition in solid dose formsuitable for transmucosal delivery, comprising a stabilizing polyol anda bioactive agent wherein the composition provides quick release of thebioactive agent after administration.
 16. The composition, according toclaim 15, wherein the composition is freeze-dried, vacuum-dried,spray-dried or dried via critical fluid extraction.
 17. The composition,according to claim 1, wherein the stabilizing polyol is in a glass form.18. The composition, according to claim 15, wherein the bioactive agentis selected from the group consisting of live and attenuated viruses,nucleotide vectors encoding antigens, bacteria and antigens.
 19. Thecomposition, according to claim 15, wherein the bioactive agent is anantigen selected from the group consisting of diphtheria, tetanus,pertussis, botulinum, cholera, Dengue, hepatitis A, C and E, haemophilusinfluenzae b, herpes virus, Hylobacterium pylori, influenza, Japaneseencephalitis, meningococci A, B and C, measles, mumps, papilloma virus,pneumococci, polio, rubella, rotavirus, respiratory syncytial virus,Shigella, tuberculosis, yellow fever and combinations thereof.
 20. Thecomposition, according to claim 15, wherein the bioactive agent isselected from the group consisting of pharmaceutical agents, subcellularcompositions, cells, proteins and peptides, peptide mimetics, hormones,D and L amino acid polymers, oligosaccharides, polysaccharides,nucleotides, oligonucleotides and nucleic acids.
 21. The composition,according to claim 20, wherein said pharmaceutical agent is selectedfrom the group consisting of anti-inflammatory drugs, analgesics,antiarthritic drugs, antispasmodics, antidepressants, antipsychotics,tranquillizers, antianxiety drugs, narcotic antagonist, antiparkinsonismagents, cholinergic agonists, chemotherapeutic drugs, immunosuppressiveagents, antiviral agents, antibiotic agents, appetite suppressants,antiemetics, anticholinergics, antihistaminic, antimigraine agents,coronary, cerebral or peripheral vasodilators, hormonal agents,contraceptives, antithromobotic agents, antihypertensive agents,cardiovascular drugs and opioids.
 22. The composition, according toclaim 21, wherein said biological modifier is an immunogen.
 23. Thecomposition, according to claim 15, wherein the bioactive agent is aprotein selected from the group consisting of enzymes, growth hormones,growth factors, insulin, monoclonal antibodies, interferons,interleukins and cytokines.
 24. The composition, according to claim 15,wherein the stabilizing polyol is selected from the group consisting ofmonosaccharides, disaccharides, trisaccharides, oligosaccharides andtheir corresponding sugar alcohols, polyhydroxy compounds such ascarbohydrate derivatives and chemically modified carbohydrates,hydroxymethyl starch and sugar copolymers, or combinations thereof. 25.The composition, according to claim 24, wherein the polyol is dextran.